Rack mechanism.



No. "5,079. Patented Doc. 2, I902.

H. mm.

BACK MECHANISM.

(Application Had my 14, 1902.) (No Model.) 3 Sheath-Shut I.

fizmzzziar Jaga @kzz- I No. 7|5,079. Patented Doc. 2, I902. H. JOHN.

RACK MECHANISM.

(Applicltion mod I, 14, 1902..)

(In Hum.) 3 SIIOQtI-SIIOOt 2.

No. 7l5,079. v Patented Doc; 2, I902.

H. JOHN. BACK MECHANISM.

(Applictflon filed my 14,- 1902.) (No Modal.) 1 3 Shoots-6h! 3.

waZzems'eax fiwezzzw' m: Nonms warns co. PHOYO-LITHCL. WASNINGTON. u. c.

UNTTED STATES PATENT OFFICE.

HUGO JOHN, OF ERFURT, GERMANY.

RACK MECHANISM.

SPECIFICATION forming part of Letters Patent N 0. 715,079, datedDecember 2, 1902. Application filed May 14, 1902. Serial No. 107,293.(No model.)

To all whont it may concern: I

Be it known that I, HUGO JOHN, manufacturer, a subject of the King ofPrussia, Emperor of Germany, residing at Erfurt, in the Kingdom ofPrussia and German Empire, have invented certain new and usefulImprovements in Rack Mechanism, of which the following is aspecification.

This invention relates to certain new and useful improvements in rackmechanism, particularly applicable for boring and cutting machines.

The invention aims to provide a rack mechanism for boring and cuttingmachines which can be operated by electric or other motors in order toincrease the efficiency of the machine as well as obtaining aconsiderable saving of time and overcome the operation of the rackmechanism manually; and to this end the invention consists of the novelcombination and arrangement of parts hereinafter more specificallydescribed, illustrated in the accompanying drawings, and particularlypointed out in the claims hereunto appended.

In describing the invention in detail referonce is had to theaccompanying drawings, forming a part of this specification, in whichlike reference characters denote corresponding parts throughout theseveral views, and in which- Figure 1 shows an elevation of acuttingmachine provided with my improved rack mechanism. Fig. 2 is apartial plan view thereof. Fig. 3 is a detail of the rack mechanism.Figs. 4 to 8, inclusive, show various positions of the rack mechanismduring the operation thereof. Fig. 9 is an enlarged detail View, brokenaway, of the rack mechanism; and Fig. 10 is a sectional plan thereof,showing the arrangement of the pawls.

Referring to the drawings by reference characters, a denotes a rack-bar,which is formed at its lower end into an eccentric-ring mounted upon adriving-eccentric n.

The reference character g denotes the pulley of a motor which isconnected to and drives the fast and loose pulleys h h, supported by anauxiliary shaft suitably journaled in the frame of the machine. Theauxiliary shaft carries a pinion which in turn drives the gear 7t,carried by the main driving-shaft Z. The latter is journaled in thesides m of the machine-frame and carries the driving-eccentric n, whichis mounted in the eccentric'ring formed on the lower end of the rack a.

The reference character 0 denotes a lever connected to aneccentric-support b, suitably mounted in the frame of the machine. Whenthe lever c is operated, it is adapted to give to the eccentric-supporta slow rotatable motion.

The reference character 01 denotes a pawl connected with the lever c.The pawl is adapted to engage the rack a, so that when the rack isoperated it will engage the pawl to move the lever c.

The reference character e denotes a rack or locking-bar, which isadapted to be engaged by the pawl d to arrest the forward movement ofthe lever 0 upon backward movement of the rack a.

The pawl d is kept against its corresponding rack a by a yoke shapedpart 0. In a similar manner the rack e is surrounded by a yoke 0 with apawl d Both pawls cland d are loosely mounted on a cross-rod d,connecting the free ends of the two arms of the lever c. The pawls d andd are kept in engagement with .their corresponding racks a and e,respectively, Without the employment of springs by their own weight andby the resistance which the material to be worked 0ffers in the upwarddirection to the lever 0 when the latter is moved downward.

When the rack at is moveddown by the rotating eccentric n, it carrieswith it the pawl d, which is, as above stated, revolubly mounted on thefree end of lever 0. During this movement the other pawl d in the yoke 0slides over the teeth of the rack e, which is pivoted in the lower partof the frame, and upon the following upward movement of the rack a thepawl cl keeps the lever c immovable until the rack a comes again inoperative engagement with pawl d, and so on, Figs. 1, 9, and 10. Theracks a and etherefore prevent alternately the lever c from movin gback, this lever being constantly together, with the pawls d and dpressed upward against the teeth of theracks by the resistance of thework.

The operation is as follows: Assuming a counter-clockwise rotation ofthe shaft Z, the

ICO

latter causes a reciprocating motion to be imparted to the rack a. Thisrack is held in engagement with the pawl 01 by a yoke 0. In movingdownward the rack a draws the pawl d downwardly with it, and as thelatter is rotatably fixed on the free end of the lever c the end-of thelatter is gradually moved through the arc of a circle 10 p, Fig. 1. Uponthe ascent or resting of the rack Cb the pawl of the locking-bar eengages with the latter and prevents backward motion of the lever c,which is acted upon, owing to the resistance of the material to beworked. As shown in Figs. 4 to 8, the rack or is on its upper sideprovided with ratchet-teeth. As the lever 0 determines the position ofthe fulcrum d of the pawl d and the yoke 0 guides the rack and is alsorotatable about 61, Figs. 1 and 3, the upper end of the rack tends toturn in clockwise direction, as indicated by the arrow I, Fig. 4.Thereby a deeper and surer engagement of the pawlwith the teeth oftherackis obtained, considering the rapid motion of the rack, than when itis manually operated. Such a safe engagement is according to Fig. 5(position II) and Fig. 6 (position III) effected so long as the rack isdrawn downwardly by the eccentric-ring a. Upon the ascent of the rack(positions IV and V, Figs. 7 and 8) the end of the rack a above the.yoke 0 tends to move out of engagement with the pawl (1, so that uponthe ascent of the rack (during which the latter is inoperative) there isno engagement of the pawl cl with the teeth of the rack. It is obviousthat with such a driving device the operation is very convenient for anefficient working of the machine.

, In order to automatically effect the disengagement of the pawl 01 fromthe teeth of the rack 11 when the lever c is turned down to a certainpoint, and consequently the cutting operation has been efiectedcompletely or up to a certain stage, an adjustable slide g is arrangedupon therack a and provided with a spring upwardly-turned projection r,Figs. 1 and 8, which glides over the face of the teeth of the rack. Onencountering the point of the pawl d the projection r lifts the pawl outof the teeth of the rack a, and thereby stops the lever c from furtherdownward movement. This automatic release is arranged for the preciseadjustment of the depth of cut of the cutter in cutting-machines andserves for the control of the cutting. It must be understood that as newunground cutters have their wider cutting edges more distant from thecutter-holders than used and partly-worn cutters it is necessary inorder to prevent the cutting edges from interfering with each other andfrom being damaged upon the use of new cutters to throw thecutting-machine driven by motor-power sooner out of engagement, and thusto move the slide q higher up than if already-worn and ground cuttersare used.

When the machine is disengaged by means of the spring projection r, thelever 0 can be brought back into its highest position (indicated in fulllines in Fig. 1) by hand by means of the handles :12. q

The handles 01 serve to move the pawls d and 6& out of engagement withtheir racks.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven lever, of a toothed bar terminating at itslower end in an eccentric-ring, operating means engaging the ring forreciprocating the bar, a pawl pivotally connected with the lever andadapted to be engaged and moved by said rack during its descent to drivethe said lever, and a yoke connected with the lever and adapted toretain the pawl against the rack.

2. In a rack-driving'mechanism for cutting and boring machines, thecombination with the driven lever, of a rack-bar, means engaging the barfor reciprocating it, a pawl pivotally connected with the lever andadapted to be engaged and moved by said rack during its descent fordriving the lever, and means for retaining the pawl against the rack.

3. In a rack-driving mechanism for cutting and boring machines,thecombination with the driven lever, of a rack-bar terminating at itslower end in an eccentric-ring, operating means engaging in the ring forreciprocating the bar, a pawl pivotally connected with the lever andadapted to be engaged and moved by said bar during its descent fordriving the lever, means connected with the lever for retaining the pawlagainst the rack, and means for locking the lever from movement duringthe ascent of the bar.

4. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a toothed bar, means engaging thebar for reciprocating it, a pawl pivotally connected with the drivenmember and adapted to be engaged and moved by said bar during itsdescent for driving the said member, and means connected with the mem-.her for retaining the pawl against the bar.

5. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a toothed bar, means engaging thebar for reciprocating it, a pawl pivotally connected with the drivenmember and adapted to be engaged and moved by said bar during itsdescent for driving the said member, means connected with the member forretaining the pawl against the bar, and means for locking the saidmember from movement during the ascent of' the said bar.

6. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a toothed bar, means engaging thebar for reciprocating it, a pawl pivotally connected with the drivenmember and. adapted to be engaged and moved by said bar during itsdescent for driving the said member, means connected with the member forretaining the pawl against the bar,

and means for automatically releasing the pawl from engagement with therack to arrest further movement of the said member.

7. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a toothed bar terminating at itslower end in an eccentric-ring, operating means engaging in the ring forreciprocating the bar, a pawl pivotally connected with the said memberand adapted to be engaged and moved'by said bar during its descent fordriving the said member, a yoke connected with the said member forretaining the pawl against the said bar, means for locking the saidmember from movement during the ascent of the bar, and means forantomatically releasing the pawl from engagement with the bar to arrestfurther movement of the said member.

8. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a reciprocatory toothed bar, a pawlpivotally connected with the said member and adapted to be engaged andmoved by said barduring its descent for driving the said member, andmeans connected with the said member and adapted to retain the pawlagainst the said bar during the reciprocating movement of the latter.

9. In a rack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a reciprocatory toothed bar, a pawlpivotally connected with the said member and adapted to be engaged andmoved by said bar during its descent for driving the said member, meansconnected with the said member and adapted to retain the pawl againstthe said bar during the reciprocating movement of the latter, and meansfor locking the said member from movement during, the ascent of the bar.

10. Inarack-driving mechanism for cutting and boring machines, thecombination with a driven member, of a reciprocatory toothed bar, a pawlpivotally connected with the said member and adapted to be engaged andmoved by said bar duringits descent fordriving the said member, meansconnected with the said member and adapted to retain the pawl againstthe said bar during the reciprocating movement of the latter, means forlocking the said member from movement during the ascent of the bar, andmeans for automatically releasing the pawl from engagement with the barto arrest further movement of the said member.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

HUGO JOHN.

Witnesses:

WILHELM BINDEWALD, ERNST EVERHARDT.

